This Training Grant, now entering its 20th year, provides support for a unique interdisciplinary predoctoral and postdoctoral training program in Immunology at the Johns Hopkins University School of Medicine. The Training Grant is the core source of funding for the Graduate Program in Immunology. The mission of this interdepartmental Program is to provide students and fellows with training in cellular, biochemical, and genetic approaches to the biology of the immune response. We seek to provide trainees with the ability to identify significant research questions in immunology, to find solutions to these questions, to think broadly and creatively about biological problems, and to communicate ideas effectively to others. The faculty has been expanded from 21 to 31 members during the previous funding period, providing increased training opportunities for students and fellows and reflecting strong institutional commitment to this area. In the process of expanding the faculty, we focused on developing important areas in immunology in which groups of faculty members with common interests could engage in complimentary and collaborative research projects. These areas include innate immunity, allergy and asthma, viral immunology, antigen processing and presentation, autoimmunity, tumor immunology, and vaccine design. In these areas the training environment is enhanced by institutional strength in relevant areas of basic science and/or clinical medicine. Cross-fertilization between basic research and clinical disease studies is an important aspect of the training environment. The predoctoral program places emphasis on rigorous training in basic biochemistry and molecular and cellular biology in addition to immunology. Progress of trainees throughout the didactic and research portions of the predoctoral training program is monitored closely through multiple mechanisms. Postdoctoral fellows have the option of selecting laboratories that focus on basic immunology or immunologic diseases. An extensive and successful program for recruiting minority students has been implemented.